Questions about Enphase IQ Combiner 3 as a subpanel

Getting ready to pull the trigger on an EV and reaching out for quotes from electricians to install a NEMA 14-50 receptacle for an EVSE in my garage. That’s the easy / more straightforward part.

The issue is at my main panel; all slots in the panel are full and already has 5 tandem breakers for various lighting and other circuits throughout the home. My IQ Combiner box is mounted next to my main panel in my basement using 2 of the 4 spaces (2 pole, 20A breakers) for two strings of panels.

The question that I have, and that the electrician didn’t immediately have the answer to, is can I use one of the open spaces inside the IQ Combiner with the appropriate sized breaker for the new circuit in the garage (i.e. does the IQ Combiner qualify as an approved “subpanel” for this purpose”? I’m hoping to avoid having to install a separate subpanel for this one additional circuit if possible.

The IQ Combiner is using line side taps with the main disconnect on the outside of the home if that matters.